#include <ostream>
template <typename T>
class myLinearList {
public:
	virtual ~myLinearList() {}
	virtual bool empty() const = 0;
	virtual int get_size() const = 0;
	virtual T& get_element(int index) const = 0;
	virtual int index_of(const T& element) const = 0;
	virtual void insert(const T&, int index) = 0;
	virtual void erase(int index) = 0;
	virtual void output(std::ostream& os = cout) const = 0;
};